The objectives of this research are to establish pathways and characterize special enzymes involved in the degradation of two diamino acids, Beta-lysine and 3,5-diaminohexanoate, by some aerobic and anaerobic bacteria. 3-5-Diaminohexanoate is an intermediate in lysine fermentation by some clostridia and a substrate for a Brevibacterium. It is oxidized to 3-keto, 5-aminohexanoate which is further converted to 2-carbon and 4-carbon compounds by a series of reactions probably involving coenzyme A thioesters of one or more intermediate amino acids. We shall attempt to establish the pathway and study the appropriate enzymes (CoA transferase, a specific thiolase, Beta-aminobutyryl-CoA deaminase). Using extracts of a Beta-lysine oxidizing Pseudomonas, we plan to apply tracer and enzymic methods to investigate further steps in the degradation of Beta-lysine, which is already known to involve 6-N- acetyl-L-Beta-lysine and 3-keto,6-acetamidohexanoate. The cleavage of the 3-keto-acid to C2 and C4 compounds, the deacetylation and the deamination of the C4 product will be examined.